Mastersound EVOLUTION 845

About the Mastersound EVOLUTION 845

The MasterSound Mastersound Evolution 845 is a high-end Italian integrated valve amplifier built as a dual-mono, pure Class A, parallel single-ended triode design. It uses four 845 power triodes, two ECC802/ECC82 pre-driver valves, and two 6SN7 driver valves, with MasterSound output transformers and zero negative feedback. The amplifier provides approximately 2 x 55 W and includes both line-level and direct/bypass inputs, with versions and documentation also listing balanced XLR connections. It has selectable 4-ohm and 8-ohm speaker outputs, automatic or semi-automatic bias depending on production revision, and a remote-controlled volume control. Available documentation identifies the model as a historical product dating from approximately 2009 onward; current listings may represent remaining stock or used examples rather than continuous current production. Specifications vary slightly between revisions and distributors, particularly input impedance, dimensions, power-consumption figures, and whether the bias is described as automatic or semi-automatic.